Baked normal map looks fine but has strange 'blocky' shapes when applied to the mesh (Overlapping UVs?)
Ok, I found the solution in the end! I realised that the problem was being caused by overlapping UV maps and mirrored geometry so I selected half of the model and then shifted the islands over by 2048px (the width of the normal map) so that they were off of the main area. I am not exactly sure why this happened, so if anyone has any insight it would be helpful, not only to me but to anyone reading this in the future. Here is an image of the adjusted UV map and the working mesh w/ normal map.